Propane, a common fuel, undergoes complete combustion in excess oxygen according to…
CHEMISTRY · Multi-part · A Level · Chemistry · Amount of substance · Amount of substance
Problem
Propane, a common fuel, undergoes complete combustion in excess oxygen according to the reaction
C3H8+5O2→3CO2+4H2O
A student plans an experiment in which exactly 44.0g of CO2 are to be collected from the combustion of propane. No numerical work is required in this problem; focus on the chemical reasoning involved.
(a) Explain, in words, why the balanced chemical equation is essential for relating the mass of CO2 to the mass of C3H8 consumed.
(b) Outline the sequential steps—identifying all units at each stage—that one would follow to determine the mass of propane required to obtain 44.0g of CO2. Do not perform the calculations.
(c) Identify the fundamental chemical law that justifies using the stoichiometric coefficients as exact mole ratios when carrying out such a mass–mass relationship.